Improvement in valve-gears



D. OB. LADD. Valve-Gear.

No. 207,607. Patented Sept. 3,1878.

UNITED STATES'PATENT OFFIoE.

DENNIS OB. LADD, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF HIS RIGHT TOGEORGE FARNSIVORTH, OF SAME PLACE.

IMPROVEMENT IN VALVE-GEARS.

Specification forming part of Letters Patent No. 207,607, datedSeptember 3, 1878; application filed December 21, 1877.

To all whom it may concern:

Be it known that I, DENNIS OB. LADD, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Automatic Governors and Out-0ffs for Steam-En gines, of whichimprovements the following is a specification, reference being had tothe accompanying drawin gs, forming a part hereof, and in which Flgure 1is a side elevation of the eccentric and of the parts governing itsaction; Fig. 2, a like representation of the parts lying between theeccentric and the rotary disk; and Fig. 3 is a horizontal centralsection of the cut-off mechanism.

Like letters of reference indicate like parts.

My invention relates to that class of governors and cut-off mechanismwhereby the movement of the valve is controlled by means of weightedlevers contained in a disk on the engineshaft.

My object is to render themechanism quickly sensltive to variations ofload and of steampressure, so as to ,maintain uniformity of speed at alltimes; to make the parts simple in their construction and operation, andso that they may be applied with facility to either new or old engines,and to economize in the use of fuel. These objects I accomplish chieflyby means of a pinion on the shaft and an engaging-rack in theeceentriedisk, all of which will be hereinafter particularly describedand set forth.

In the drawing, A represents the engineshaft. 13 is a disk, rigidlymounted on the shaft A. O is a hub or pinion,rigidly attached to theengine-shaft. a, are cogs on a part of the periphery of the pinion O. Dis a fixed collar on the pinion (l, and E is a removable collar thereon.F is the eccentric-disk, and G is the eccentric strap or ring. Theeccentric F has in it the elongated central opening F, on one side ofwhich are the cogs a, constituting the rack F, the cogs of which areadapted to engage the cogs a. The eccentricdisk is arranged between thecollars D and E, and, excepting as its movement is restricted by theengagement of the cogs a and a, and by its connection with 'the sleeve,hereinafter referred to, may be regarded as freely mounted on the pinionG.

H is a sleeve on the shaft A; and I, J, K, and L are arms projectingfrom the sleeve H, and lying in parallel pairs. M and N are weightedlevers, pivoted to the disk B at b b, as shown. These levers extend inopposite directions, and the arm M is connected to the arm K by means ofthe link 0, and the arm N to the arm L by means of the link 0, theselinks being pivoted to the arms to which they are connected.

P P are springs to draw the free and weighted ends of the arms or leversM and N in toward the shaft A, or to produce a centripetal movement ofthe weights, when the centrifugal force produced by the rotation of theshaft is diminished, or tends to become lessened either on account oflow steam-pressure or of an increased load.

Q is a lug rigidly attached to the eccentricdisk F; c is a pinprojecting from the arm J into a radial slot in the lug Q. R is a stoprigidly fastened to the disk 1?, and having therein the curved slot d. eis a pin extending from the arm I into the slot (1. S is a spring to aidin returning the parts to their respective places durin g thecentripetal movement of the weighted levers.

It will be perceived that when the shaft A is rotated during the actionof the engine the weighted ends of the levers M and N will move outwardas soon as the centrifugal force is sufficient to overcome the force ofthe springs P I and S. This outward movement of the weighted leversturns the sleeve H on the shaft A, and hence the arm J is carried aroundin the same direction, and this latter arm, being the centrifugal forceis overcomeby-the force of the springs the weighted ends. of the leversM and N will move centripetally, and the movements already describedwill be reversed.

It will be perceived, therefore, that the steam will be cut off earlieror later in the stroke of the piston, as may be required, to -maintainuniformity of speed under .all variations of load and steam-pressure.

The movement of the eccentric-disk F may be limited by the length of theslot d; but it is not essential that this slot should be employed forthat purpose, and it is obvious that othermeans may be used to controlthe distance moved by any of the parts described. The spring S, whenemployed as shown, takes up any lost motion that might otherwise resultfrom the engagement of-the teeth or cogs a and a.

It is not essential that the sleeve H should have four arms; neitherneed the weighted'xlevers be connected to the sleeve precisely-as shown.

It will also be perceived that-the throwmay be varied fromfull throw-tonone,--it beingunderstoodthat the eccentric-is rotated withthe shaftbesides being moved automatically in the manner described during itsrotation. It may also be applied to any enginewith facility, and-issimple in construction and operation. Also, by utilizing all, ornearly-all, the steam without unnecessary waste, a great-saving of fuelis effected.

Itmay be observed that, if-the rack F be madein-the-arc of a circle,havingthepin c as a center, the pin need not work in a slot, but in aclosely-fitting hole. It is not my intention to be restricted by mereform.

Having thus described .my invention, what "I claim asnew, and desire tosecure by Let- :ters Patent, is-- sleeve mounted on'the same shaft andcontrolled-byweightedlevers and springs, substantially as andforthe-purposes specified.

'3. 'The combination of :the shaft A, disk B, pinionO, racked eccentricI sleeve H, two or more levers, M N, connected to the said sleeve,

and springs :for producing centripetal movement of the said levers,substantially as and for the purposes specified.

DENNIS OB. LADD.

WVitnesses:

JAMES H. GoYNE, S. S. SoHoFF.

